Pallet changing apparatus

ABSTRACT

A pallet changing apparatus adopting a table  4  capable of moving back from and forth for a side of a turning shaft  1  and having a oscillating portion  41  for placing workpieces W, W by means of pallets P, P so as to oscillate freely by an upright portion  42  at the leading end of the table  4 , wherein the turning shaft  1  covers a turning supporting portion  11  at its lower end side and turns together with a pallet changing arm  3  and moves freely in a vertical direction, and an insertion and removal hollow space  20  is provided, at the covering region, and allows the upright portion  42  to be inserted into the insertion and removal hollow space  20  and removed from the insertion and removal hollow space  20.

TECHNICAL FIELD

This invention relates to a pallet changing apparatus which arranges aturning shaft for supporting a pallet changing arm transferring a palletbetween a pallet setup base and a table in such a manner so as to movefreely in a vertical direction and also in a state of being stationaryin a horizontal direction.

BACKGROUND ART

The pallet changing apparatus equips, as essential constituents, thepallet setup base which places a pallet, the table which places aworkpiece with a state of before processing or after processed by meansof the pallet, and the turning shaft which holds pallet changing armsextended on both sides and also turns along a horizontal directiontogether with the pallet changing arms.

The turning shaft equips a turning supporting portion which allows aball bearing device, etc., to turn smoothly below a site which supportsthe pallet changing arm. In recent years, there is favorably adoptedsuch a configuration that has a covering portion which covers from abovea turning supporting portion in order to prevent chips generated due tocutting of workpieces by a main shaft from entering into the turningsupporting portion.

On the other hand, for the sake of convenience of cutting work by themain shaft, the table often equips a rising portion which has aoscillating center axis at a leading end of the table on the side of theturning shaft for allowing a region which places a workpiece by means ofa pallet to oscillate freely and also equips a oscillating portion inwhich the region is supported by the turning shaft.

Where the table having the above-described rising portion moves backfrom and forth for a side of the turning shaft having the coveringportion, the presence of the rising portion inevitably hinders theturning of the pallet changing arm.

Further, the fact that a certain space is occupied by the turning shaftfirmly fixing the covering portion makes more worse state for theabove-mentioned is necessary for hindering problem.

In order to avoid the above-described problem, instead of the tablewhich has the rising portion and moves back from and forth for a side ofthe turning shaft, there can be conceived such a configuration that, asshown in FIG. 5, a turning shaft 1 which firmly fixes a covering portion2 is arranged at a side portion in a direction at which a table 4 whichhas a oscillating portion 41 and a rising portion 42 at the leading endside of the table moves back and forth, a pallet setup base 5 isarranged at a side portion further away from the table 4, and also thedirection at which the table 4 moves back and forth is orthogonal to adirection at which the turning shaft 1 and the setup base 5 arearranged.

However, in the case of the configuration of the above-describedarrangement, in addition to a space region in a direction at which thetable 4 moves back and forth, a space region is also necessary at theside portion for changing a pallet. Thereby, it is impossible to achievea compact pallet changing apparatus.

Where the configuration in which the table moves back from and forth fora side of the turning shaft is compared with the above-describedconfiguration in which the constituents are arranged at the sideportions, there is found such a relationship that the formerconfiguration is larger in a region in which the table overlaps with thepallet changing arm in a vertical direction than the latterconfiguration. In the former configuration, it is possible to set thespace necessary for turning of the pallet changing arm small.

Instead of the configuration in which the constituents are arranged atthe side portions, where there is retained the configuration in whichthe table having the rising portion and the oscillating portion movesback from and forth for a side of the turning shaft, it is possible toconceive such a configuration that, on transfer of a pallet by using atable and a setup base, a turning shaft moves from an intermediateposition between the table and the setup base to a position suitable forthe transfer.

However, in the case of the above-described configuration, it isessential that not only the table moves back and forth but also theturning shaft moves. Therefore, complicated control becomes essential.

With regard to a pallet changing apparatus, various publicly-knowntechnologies have been disclosed.

Of these publicly known technologies, in Patent Document 1, anoscillatory table 6 is moved by a table-driving device 30. However, asupporting shaft 42 which corresponds to the turning shaft is arrangedat an oblique side portion in a direction at which the table 6 moves(FIGS. 1, 2, 4: the supporting shaft 42 is not provided with a coveringportion).

However, as compared with the case of the orthogonal state shown in FIG.5, the configuration of the above arrangement is such that a spaceregion of the side portion necessary for changing a pallet is slightlysmaller. This configuration is also unable to achieve a compact palletchanging apparatus.

In Patent Document 2, a turning member 34 which corresponds to thepallet changing arm is installed on a side of a table 6 which canoscillate along a oscillating axis 19 provided at a supporting portion17 which corresponds to the rising portion, and also one of or both ofthe table 6 and a turning member 34 are allowed to move back and forthwith each other (FIG. 2 and claim 1: the turning member 34 is notprovided with a covering portion).

However, the above-described configuration is also similar to theconfiguration shown in FIG. 5 and the configuration described in PatentDocument 1 in that it is unable to achieve a compact pallet changingapparatus.

Additionally, in the case of the above-described configuration, thetable 6 is not only required to move back from and forth for a side of alower region of the main shaft, but the turning member 34 and/or thetable 6 are also required to move back and forth with each other in adirection different from the above-described back and forth movement.Therefore, complicated control is essential.

As described so far, although referring the publicly known technologies,proposal is not found for compact configuration of a pallet changingapparatus at all which supports a workpiece so as to oscillate by meansof a pallet and which is provided with a rising portion having aoscillating center axis at the leading end of the turning shaft of thetable which moves back from and forth for a side of the turning shaftand also covers from above a turning supporting portion at a lower endof the turning shaft.

PRIOR ART DOCUMENTS Patent Documents

-   [Patent Document 1] Japanese Published Unexamined Patent Application    No. 2004-160601-   [Patent Document 2] Japanese Published Unexamined Patent Application    No. 2015-205356

SUMMARY OF INVENTION Problem to be Solved

An object of the present invention is to provide a compact configurationof a pallet changing apparatus which equips a rising portion with aoscillating center axis at a leading end of the table that supports aworkpiece by oscillatory state by means of a pallet and moves back fromand forth for a side of the turning shaft and which covers the turningsupporting portion at a lower end of the turning shaft from upper side.

Solution to Problem

In order to solve the above problem, basic configurations of theinvention are composed of:

(1) A pallet changing apparatus which equips a turning shaft forsupporting a pallet changing arm transferring a pallet between a palletsetup base and a table in such a manner so as to move freely in avertical direction and also in a state of being stationary in ahorizontal direction,

wherein the table moves back from and forth for a side of the turningshaft and also equips a rising portion at the leading end of the tableon the side of the turning shaft and a oscillating portion which issupported by means of a oscillating center axis of the rising portion soas to oscillate freely and also places a workpiece by means of a pallet,

wherein the turning shaft firmly fixes a covering portion which covers aturning supporting portion positioned at a lower end side of the turningshaft from upper side, and the covering portion equips an insertion andremoval hole which allows the rising portion to be inserted and removedfreely, and

wherein the pallet changing arms equip a pallet supporting portionextending in a horizontal direction for transferring a pallet on bothsides from side positions of the insertion and removal hole, and

(2) A pallet changing apparatus which equips a turning shaft forsupporting a pallet changing arm transferring a pallet between a palletsetup base and a table in such a manner so as to move freely in avertical direction and also in a state of being stationary in ahorizontal direction,

wherein the table moves back from and forth for a side of the turningshaft and equips a rising portion at the leading end of the table on theside of the turning shaft and a oscillating portion which is supportedby means of a oscillating center axis of the rising portion so as tooscillate freely and also places a workpiece by means of a pallet,

wherein the turning shaft firmly fixes a movable covering portion whichextends the pallet changing arms on both sides, and a stationarycovering portion which covers a turning supporting portion positioned ata lower end side of the turning shaft is arranged on a floor below themovable covering portion from upper side, the stationary coveringportion an insertion and removal hole which allows the rising portion tobe inserted and removed freely, and

wherein the pallet changing arms equip a pallet supporting portionextending in a horizontal direction for transferring a pallet and across-linking extending portion for cross-linking the positions of theboth sides of the movable covering portion.

Advantageous Effects of Invention

This invention which is based on the basic configurations (1) and (2)equips the insertion and removal hole of the covering portion (in thecase of the basic configuration (1)) or the insertion and removal holeof the stationary covering portion (in the case of the basicconfiguration (2)) which allows the rising portion positioned at theleading end of the table on the side of the turning shaft and a certainregion of the table connected to the rising portion to be inserted andremoved freely. Therefore, where the rising portion is inserted into theinsertion and removal hole, no hindrance occurs at all to turning of thepallet changing arms (in the case of the basic configuration (1))extended on both sides from the covering portion or turning of thepallet changing arms (in the case of the basic configuration (2))extended on both sides from the movable covering portion.

Further, by inserting the rising portion positioned at the leading endof the table into the insertion and removal hole, a pallet placed on thetable can be arranged in a closed state to the turning shaft side,although the covering portion (in the case of the basic configuration(1)) or the stationary covering portion (in the case of the basicconfiguration (2)) is present between the table and the pallet setupbase.

In other words, since a pallet can be arranged in a state of being madeclose, the pallet changing arms can be designed shorter in length ascompared with the prior arts, thus making it possible to achieve acompact pallet changing apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a configuration of the basic configuration (1), (a) shows aside sectional view along a direction at which the table moves back andforth (the covering portion and the pallet changing arms are shown by asectional view, and other constituents are shown by a side elevationalview. Further, a patterned portion shows a region other than the risingportion and the oscillating portion of the table), and (b) shows a frontview of the covering portion which is a side at which the insertion andremoval hole is provided.

FIG. 2 shows a configuration of the basic configuration (2), (a) shows aside sectional view along a direction at which the table moves back andforth (the covering portion and the pallet changing arms are shown by asectional view, and other constituents are shown by a side elevationalview. Further, a patterned portion shows a region other than the risingportion and the oscillating portion of the table), and (b) shows a frontview of the covering portion which is a side at which the insertion andremoval hole is provided.

FIG. 3 is a drawing which explains motions of a pallet changingapparatus of the basic configuration (1) which shows steps covering thestart of changing a pallet and up to the completion thereof, as thefirst step in which the rising portion at the leading end of the tableon the side of the turning shaft is inserted into the covering portion.

FIG. 4 is a drawing which explains motions of a pallet changingapparatus of the basic configuration (2) which shows steps covering thestart of changing a pallet and up to the completion thereof, as thefirst step in which the rising portion at the leading end of the tableon the side of the turning shaft is inserted into the covering portion.

FIG. 5 is a top view which shows a state that the turning shaft and thepallet setup base are arranged in a direction which is orthogonal to adirection at which the table moves back and forth.

DESCRIPTION OF EMBODIMENTS

As described in the Technical Field, each of the basic configuration (1)shown in FIG. 1 and the basic configuration (2) shown in FIG. 2 standson a technically basic premise that the table 4 moves back from andforth for a side of the turning shaft 1 and is also provided with theoscillating portion 41 which is supported so as to oscillate freely bymeans of a oscillating center axis 420 of the rising portion 42positioned at the leading end of the table on the side of the turningshaft 1 and places workpieces W, W′ by means of pallets P, P′.

In the basic configurations (1) and (2), the oscillating portion 41which supports the workpieces W, W′ by means of the supporting frame 40inside the table 4 and a supporting surface which supports the palletsP, P′ by means of the supporting frame 50 inside the setup base 5 areboth arranged so as to be lower than a position at which a supportingportion of the pallet changing arm 3 turns. Therefore, the supportingportion is arranged above the oscillating portion 41 and the supportingsurface of the setup base 5.

As shown in FIG. 1, the pallet changing arms 3 of the basicconfiguration (1) are extended in a horizontal direction from both sidesof side portions of the covering portion 2 firmly fixed to the turningshaft 1. The supporting portion positioned at the leading end of theextension turns down to a position below the pallets P, P′ supported bythe supporting frames 40, 50 and is also able to move to the oscillatingportion 41 and an upper region of the supporting surface of the setupbase 5 together with the turning shaft 1 with the pallets P, P′ ofsupported state.

As shown in FIG. 2, the pallet changing arms 3 of the basicconfiguration (2) are also extended on both sides from the movablecovering portion 21 firmly fixed to the turning shaft 1. The supportingportion at the leading end thereof turns down to a position below thepallets P, P′ supported by each of the pallet supporting frames 40, 50and is also able to move to the oscillating portion 41 and an upperregion of the supporting surface of the setup base 5 together with theturning shaft 1 with the pallets P, P′ of supported state.

Then, as shown in FIG. 2 (a), the pallet changing arms 3 of the basicconfiguration (2) are each provided with a cross-linking extendingportion 31 which cross-links between the pallet supporting portion andthe positions of the both sides of the movable covering portion 21.

In FIG. 2 (a), (b), the cross-linking extending portion 31 is extendedobliquely from a side of the movable covering portion 21 and formsapproximately an L-letter shape. Various shapes can be adopted as thecross-linking extending portion 31.

Concretely, there can be adopted a shape in which the cross-linkingextending portion 31 is curved sequentially by extending from a side ofthe movable covering portion 21 in a horizontal direction and forms aconnection with the supporting portion, and additionally, an obliquelylinear shape in which it extends from a side of the movable coveringportion 21 and reaches the supporting portion.

As described so far, shape of the pallet changing arm 3 of the basicconfiguration (1) and that of the basic configuration (2) are differentwith each other. However, at a stage when the rising portion 42 of thetable 4 is inserted into the insertion and removal hole 20, the risingportion 42 cannot be a hindrance to turning of the pallet changing arm3.

In fact, the insertion and removal hole 20 often allows not only therising portion 42 but also the oscillating portion 41 and a certainregion of the table 4 such as a lower region which supports theoscillating portion 41 indicated by a dotted patterned region in FIG.1(a) and in FIG. 2(a) to be inserted into the intersection and removalhole 20 or removed freely from the insertion and removal hole 20.

The turning shaft 1 of the basic configuration (1) is characterized inthat it can adopt a simple configuration in which one covering portion 2is firmly fixed and the pallet changing arm 3 is extended from thecovering portion 2 in a horizontal direction.

The covering portion 2 of the basic configuration (1) covers the turningsupporting portion 11 positioned at a lower end of the turning shaft 1,but is not in contact with a floor surface as long as it integrallyturns with the turning shaft 1.

However, where such a configuration is adopted that the lower end of thecovering portion 2 is below from a position at which the pallet changingarm 3 is extended and also arranged in the vicinity of the floor, it ispossible to perform sufficiently functions of the covering portion 2which prevents chips from entering into the turning supporting portion11.

The turning shaft 1 of the basic configuration (2) firmly fixes themovable covering portion 21 which extends the pallet changing arms 3 onboth sides above and achieves turning and vertical movement in anintegral manner. It has a region which overlaps at least partially withthe movable covering portion 21 in a vertical direction below themovable covering portion 21. A stationary covering portion 22 coveringthe turning supporting portion 11 positioned at the lower end of theturning shaft 1 and an insertion and removal hole 20 is provided at thestationary covering portion 22.

In the case of the basic configuration (2), as described previously, thepallet changing arm 3 is extended from the movable covering portion 21,and forms a relatively complicated shape. However, the stationarycovering portion 22 is not connected to the pallet changing arm 3,thereby eliminating the need for such strength that is required forsupporting the pallet changing arm 3, as compared with the coveringportion 2 of the basic configuration (1). It is, therefore, possible touse a metal plate or a plastic plate which is thinner than the coveringportion 2 of the basic configuration (1).

Further, the stationary covering portion 22 is arranged on the floorsurface below, thus making it possible to prevent chips from enteringinto the turning supporting portion 11 positioned at a lower end side ofthe turning shaft 1.

Especially in the case of a configuration that the lower end side of thestationary covering portion 22 is firmly fixed on a floor, it ispossible to completely prevent flying chips from entering thereinto.

Although it is essential that the turning shaft 1 of the basicconfigurations (1) and (2) turns together with the pallet changing arm 3and also moves freely in a vertical direction, in order to achieve theabove-described turning and vertical movement, as shown in FIG. 1(a),(b) and FIG. 2(a), (b), the driving portion 12 is connected to theturning shaft 1 and also firmly fixed to a floor surface or a wallportion. Thereby, it is firmly fixed to the fixed frame 13 which is in afixed state and able to drive the turning and vertical movement.

In the basic configurations (1) and (2), as the first step of insertingthe rising portion 42 of the table 4 and a certain region of the table 4connected to the rising portion 42 into the insertion and removal hole20, operation of changing the pallets P, P′ from starting and untilfinishing can be achieved by the following processes, as shown in FIG. 3and FIG. 4.

Process (a): insertion of the rising portion 42 of the table 4 (however,in most cases, the rising portion 42 and a certain region of the table 4connected to the rising portion 42) into the insertion and removal hole20,

Process (b) : integral turning of the pallet changing arms 3 in astand-by state together with the turning shaft 1,

Process (c): movement of pallets P, P′ supported by the supporting frame40 in the oscillating portion 41 of the supporting portion of the palletchanging arm 3 and that of the pallets P, P′ supported by the supportingframe 50 in the setup base 5 by downward turning,

Process (d): upward movement of the turning shaft 1 of the palletchanging arms 3 which support the pallets P, P′ and the covering portion2 (in the case of the basic configuration (1)) or the movable coveringportion 21 (in the case of the basic configuration (2)),

Process (e): 180 degree-turning of the pallet changing arms 3 whichsupport the pallets P, P′,

Process (f): downward movement of the turning shaft 1 of the palletchanging arms 3 which support the pallets P, P′ and the covering portion2 (in the case of the basic configuration (1)) or the movable coveringportion 21 (in the case of the basic configuration (2)) and placement ofeach of the pallets P, P′ on the supporting frame 40 of the oscillatingportion 41 and on the supporting frame 50 of the setup base 5,

Process (g): return to an original position by turning of the palletchanging arm 3.

As described above, in a state that the rising portion 42 of the table 4(however, in fact, in most cases, a certain region of the table 4connected to the rising portion 42) is accommodated inside the insertionand removal hole 20 of the covering portion 2, the basic configurationsof (1) and (2) are able to smoothly change the pallets P, P′ whichrespectively place workpieces W, W′ by a series of turning and verticalmovement.

Hereinafter, a description will be given with reference to the examples.

EXAMPLE 1

Example 1 is characterized in that the covering portion 2 of the basicconfiguration (1) and the stationary covering portion 22 of the basicconfiguration (2) are each provided with a door (not shown) for openingand closing the insertion and removal hole 20.

Installation of the door makes it possible to prevent chips fromentering into the turning supporting portion 11 by closing the door evenafter insertion of the rising portion 42 and a certain region of thetable 4 through the insertion and removal hole 20.

With a consideration on a space necessary for opening and closing thedoor, a sliding door is more preferable than a revolving door.

EXAMPLE 2

Example 2 is characterized in that the basic configurations (1) and (2)achieve a state that the rising portion 42 inserted into the insertionand removal hole 20 is arranged in the vicinity of the surface of theturning shaft 10.

In Example 2, the pallet changing arms 3 can be made shortest in lengthby arranging the rising portion 42 in the vicinity, thereby achieving acompact pallet changing apparatus.

INDUSTRIAL APPLICABILITY

As described so far, in the present invention in which the risingportion can be inserted into the insertion and removal hole provided atthe covering portion (in the case of the basic configuration (1)) or atthe stationary covering portion (in the case of the basic configuration(2)), the presence of the rising portion does not hinder turning of thepallet changing arms. Further, the present invention is remarkablyinnovative in achieving a compact pallet changing apparatus and can beused in all types of machine tools that require pallet change.

REFERENCE SIGNS LIST

-   1: Turning shaft-   11: Turning supporting portion-   12: Driving portion for turning shaft-   13: Fixed frame-   2: Covering portion-   20: Insertion and removal hole-   21: Movable covering portion-   22: Stationary covering portion-   3: Pallet changing arm-   31: Cross-linking extending portion-   4: Table-   40: Supporting frame for pallet arranged at oscillating portion-   41: oscillating portion of table-   42: Rising portion of table-   420: oscillating center axis of rising portion-   5: Setup base-   50: Supporting frame for pallet arranged on setup base-   6: Machine tool provided with main shaft, etc.-   P, P′: Pallet-   W, W′: Workpiece

What is claimed is:
 1. (canceled)
 2. (canceled)
 3. A pallet changingapparatus comprising: a pallet setup base, a table, at least one palletchanging arm configured for transferring a pallet between the palletsetup base and the table, a turning shaft for supporting the at leastone pallet changing arm in a manner such that the at least one palletchanging arm moves freely in a vertical direction, wherein the table isconfigured to move back from and forth to a side of the turning shaft,the table including: an upright portion extending upwardly from and at aleading end of the table on a side of the table that is closest to theturning shaft, and an oscillating portion which is supported by theupright portion so as to oscillate freely about an oscillating centeraxis so as to position a workpiece via a pallet mountable to theoscillating portion, the pallet changing apparatus further comprising: amovable covering portion firmly fixed to the turning shaft and whichextends the pallet changing arms on opposite sides thereof, and astationary covering portion which covers a turning supporting portion ata lower end of the turning shaft and which is arranged on a floor belowthe movable covering portion, the stationary covering portion includingan insertion and removal hollow space which allows the upright portionto be inserted and removed freely therethrough, and wherein the at leastone pallet changing arm includes a pallet supporting portion extendingin a horizontal direction, the pallet supporting portion configured fortransferring a pallet from a position on one side of the pallet changingapparatus, at which side of the pallet changing apparatus the insertionand removal hollow space is located, to a position on an opposite sideof the pallet changing apparatus, and a cross-linking extending portionfor cross-linking positions of opposite sides of the movable coveringportion.
 4. The pallet changing apparatus according to claim 3, whereinthe stationary covering portion includes a lower end firmly fixed on thefloor.
 5. The pallet changing apparatus according to claim 3, whereinthe insertion and removal hollow space allows the upright portion and acertain region of the table connected to the upright portion to beinserted freely into the insertion and removal hollow space and removedfreely from the insertion and removal hollow space.
 6. The palletchanging apparatus according to claim 3, further comprising a door foropening and closing the insertion and removal hollow space.
 7. Thepallet changing apparatus according to claim 3, wherein the uprightportion, when inserted into the insertion and removal hollow space, isarranged in the vicinity of an outer surface of the turning shaft. 8.The pallet changing apparatus according to claim 4, wherein theinsertion and removal hollow space allows the upright portion and acertain region of the table connected to the upright portion to beinserted freely into the insertion and removal hollow space and removedfreely from the insertion and removal hollow space.
 9. The palletchanging apparatus according to claim 4, further comprising a door foropening and closing the insertion and removal hollow space.
 10. Thepallet changing apparatus according to claim 5, further comprising adoor for opening and closing the insertion and removal hollow space. 11.The pallet changing apparatus according to claim 4, wherein the uprightportion, when inserted into the insertion and removal hollow space, isarranged in the vicinity of an outer surface of the turning shaft. 12.The pallet changing apparatus according to claim 5, wherein the uprightportion, when inserted into the insertion and removal hollow space, isarranged in the vicinity of an outer surface of the turning shaft. 13.The pallet changing apparatus according to claim 6, wherein the uprightportion, when inserted into the insertion and removal hollow space, isarranged in the vicinity of an outer surface of the turning shaft.